Surface Activity and Cleavability of Gemini Surfactants Featuring Hydrophilic Spacer Groups

摘要

In this study we prepared and characterized a series of novel ester-linked gemini surfactants, featuring ester bonds in their structures, through the reactions of polyethylene glycol (PEG400) with various fatty acids (C8-C18). These gemini surfactants exhibit excellent surface activities, as evidenced by their surface tension, wetting power, and low-foaming and buffer abilities. We examine the influence of the concentrations of the ester-linked gemini surfactants on the surface tension, from which we obtain the critical micelle concentrations. Under basic conditions, each of these cleavable surfactants decomposes into a water-insoluble fatty acid and two water-soluble products; in contrast, they are stable under neutral and acidic conditions.